B0429 - Temperature Control #3 Rear Circuit Range/Performance
It means that there is a difference between the commanded and actual positions of the rear air mix door. I've been told that it does not take much to set that DTC. It seems to be rather common. Had it myself. If you are not having any problems controlling rear seat temperatures, clear it and forget it.
im gonna have to check my rear temp controls cause no one rides in the back so its never been turned on and as far as pcm im gonna go out an check again right now cause that was the only code that showed up as far as current be back in a few thanks for the help